RHSA-2026:49211HighCVSS 7.8

Red Hat Security Advisory: kernel security, bug fix, and enhancement update

Published
July 31, 2026
Last Modified
July 31, 2026

🔗 CVE IDs covered (3)

CVE-2025-68211 →CVE-2026-46303 →CVE-2026-64530 →

📋 Description

CVE-2025-68211 — kernel: ksm: use range-walk function to jump over holes in scan_get_next_rmap_item CVE-2026-46303 — kernel: isofs: validate Rock Ridge CE continuation extent against volume size CVE-2026-64530 — kernel: net: sched: UAF via missing handler for TC_ACT_CONSUMED in tcf_qevent_handle

🎯 Affected products200

  • Red Hat Enterprise Linux AppStream (v. 10)
  • Red Hat Enterprise Linux BaseOS (v. 10)
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • Red Hat Enterprise Linux Real Time (v. 10)
  • Red Hat Enterprise Linux Real Time for NFV (v. 10)
  • kernel-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-0:6.12.0-211.42.1.el10_2.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-0:6.12.0-211.42.1.el10_2.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-0:6.12.0-211.42.1.el10_2.src as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-0:6.12.0-211.42.1.el10_2.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-core-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debug-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debug-core-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debug-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • kernel-64k-debug-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debug-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • kernel-64k-debug-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux Real Time (v. 10)
  • kernel-64k-debug-devel-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • kernel-64k-debug-devel-matched-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • kernel-64k-debug-modules-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debug-modules-core-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debug-modules-extra-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • kernel-64k-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • kernel-64k-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • kernel-64k-debuginfo-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux Real Time (v. 10)
  • kernel-64k-devel-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • kernel-64k-devel-matched-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
  • kernel-64k-modules-0:6.12.0-211.42.1.el10_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 10)
  • +170 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture. Because of this proactive approach, a patch may be associated with a CVE assignment at a future date. Retroactive CVE assignments are always documented in the corresponding errata and on Red Hat's CVE pages. We strongly advise against delaying updates, as doing so may leave your system exposed when protections are already available. Workaround: To reduce exposure, restrict the ability of untrusted users to mount ISO images. If the `isofs` kernel module is not essential for system operation, it can be prevented from loading. To blacklist the `isofs` module: 1. Create or edit `/etc/modprobe.d/blacklist-isofs.conf` and add: ``` blacklist isofs install isofs /bin/true ``` 2. Regenerate the initramfs to apply the change: ```bash dracut -f -v ``` 3. A system reboot is required for this change to take full effect. This action may affect functionality requiring ISO 9660 filesystem mounts. Workaround: To mitigate this issue, avoid configuring the Linux kernel's traffic control (tc) subsystem with the RED queue discipline (`red`) that includes `qevent early_drop` and an `action ct` filter on interfaces processing fragmented UDP streams. This specific configuration is required to trigger the use-after-free vulnerability.

🔗 References (6)